Brake Questions (Sorry)

gf4_22 · 02-27-2025, 10:11 PM

Hello, I am a relatively new member of NASIOC here, and with my hours poring over the available threads relating to braking upgrades I have come to a well-informed decision but I still have questions unanswered.

I have a 1999 Impreza Outback Sport with the 2.2l and a 5spd manual.
I have a set of 3 2018 Crosstrek STi B3110FL051 18" wheels that I intend to find a 4th one of which will be put on said OBS. (I found a deal for 3x for $300 total)
I know I will be searching for '06-'07 STi Gold Calipers, purchasing Stainless Steel hoses for, and sourcing rear knuckles to convert my OBS to 4-wheel disc brakes.

What do I need to fit these super sick calipers on my Impreza? From what I understand the fronts should be direct replacement + calipers, but the rears are more tricky. Do I need an adapter bracket (e.g. Torque Solutions TS-SU-317) if I replace the rear dust shields with replacement 2006 STi shields? Are the gold STi calipers necessarily worth the price difference compared to the '06-'07 red Subaru/FHI calipers?

Thanks in advance, sorry again for the age old "How break work, need betterer looking stoppers" question.

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Jack · 02-28-2025, 09:29 AM

You have a car that could benefit from the old school brake upgrades those of us with GC8's had back in the day. A great upgrade that's far cheaper than anything STi is the "UK STi" = 06-07 WRX front 4 piston calipers. The 2.5RS rotors are the same size so can be used. The front upgrade mainly gets you better 4 piston calipers and a larger brake pad which on the track increases cooling and thermal mass, so it takes longer to overheat. For the rear, if your knuckles match the 2.5RS up to 2001, you can do a simple upgrade using the 2.5RS caliper and pads but with the caliper bracket from a Legacy, Outback or the like and a rotor to match. This is called an H6 upgrade.

I had this setup on my 01 2.5RS which was tracked extensively and it was a great, properly balanced setup. I can't see the need of an STi setup unless you're upping the engine to something 300 hp. On the street, none of this really helps you at all and for autocross, because it takes longer to heat up, it's actually a downgrade. If you just want the car to look cool, then go for it. With my autocross and roadrace background, I tend to look for effective solutions that don't break the bank.

02-27-2025, 10:11 PM	#1
gf4_22 Scooby Newbie Member#: 539174 Join Date: Sep 2024 Vehicle: 1999 Impreza OBS Silver 2-tone	Brake Questions (Sorry) Hello, I am a relatively new member of NASIOC here, and with my hours poring over the available threads relating to braking upgrades I have come to a well-informed decision but I still have questions unanswered. I have a 1999 Impreza Outback Sport with the 2.2l and a 5spd manual. I have a set of 3 2018 Crosstrek STi B3110FL051 18" wheels that I intend to find a 4th one of which will be put on said OBS. (I found a deal for 3x for $300 total) I know I will be searching for '06-'07 STi Gold Calipers, purchasing Stainless Steel hoses for, and sourcing rear knuckles to convert my OBS to 4-wheel disc brakes. What do I need to fit these super sick calipers on my Impreza? From what I understand the fronts should be direct replacement + calipers, but the rears are more tricky. Do I need an adapter bracket (e.g. Torque Solutions TS-SU-317) if I replace the rear dust shields with replacement 2006 STi shields? Are the gold STi calipers necessarily worth the price difference compared to the '06-'07 red Subaru/FHI calipers? Thanks in advance, sorry again for the age old "How break work, need betterer looking stoppers" question. * Registered users of the site do not see these ads.

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02-28-2025, 09:29 AM	#2
Jack Add Lightness Moderator Member#: 13699 Join Date: Dec 2001 Chapter/Region: NESIC Location: Hopkinton, MA Vehicle: 2021 Building It Better	You have a car that could benefit from the old school brake upgrades those of us with GC8's had back in the day. A great upgrade that's far cheaper than anything STi is the "UK STi" = 06-07 WRX front 4 piston calipers. The 2.5RS rotors are the same size so can be used. The front upgrade mainly gets you better 4 piston calipers and a larger brake pad which on the track increases cooling and thermal mass, so it takes longer to overheat. For the rear, if your knuckles match the 2.5RS up to 2001, you can do a simple upgrade using the 2.5RS caliper and pads but with the caliper bracket from a Legacy, Outback or the like and a rotor to match. This is called an H6 upgrade. I had this setup on my 01 2.5RS which was tracked extensively and it was a great, properly balanced setup. I can't see the need of an STi setup unless you're upping the engine to something 300 hp. On the street, none of this really helps you at all and for autocross, because it takes longer to heat up, it's actually a downgrade. If you just want the car to look cool, then go for it. With my autocross and roadrace background, I tend to look for effective solutions that don't break the bank.